/Engine/Plugins/Experimental/MeshModelingToolsetExp/Source/MeshModelingToolsExp/Public/MeshVertexSculptTool.h
OnDetailsPanelRequestRebuild is broadcast by the tool when it detects it needs to have it's details panel rebuilt outside of normal rebuilding triggers, such as changing property set objects. This is useful in rare circumstances, such as when the tool is using detail customizations and tool properties are changed outside of user interactions, such as via tool preset loading. In these cases, the detail customization widgets might not be updated properly without rebuilding the details panel completely.
typedef TMulticastDelegate_NoParams< void > OnInteractiveToolDetailsPanelRequestRebuild